STOCK BASED COMPENSATION - Expense Resulting from Stock Option Awards and ESPP (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 21,750	$ 17,773	$ 17,457
Stock Options | Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	92	52	120
Stock Options | Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	18,541	15,214	15,212
Restricted Stock Units (RSUs) | Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,484	1,267	1,116
ESPP shares | Selling, general and administrative expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,633	$ 1,240	$ 1,009